Telephone-exchange system



H. P. CLAUSEN AND C. L. GOODRUM.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JULY 19. 1919.

Patented Jan. 17, 1922.

UNITED STATES PATIENT OFFICE.

HENRY ROLAUSEN, OF MOUNT VERNON,

AND CHARLES L. GOODRUM, 01 NEW YORK,

N. Y., ASSIGNORS "10 WESTERN ELECTRIC COMPANY, INCORPORATED, 01 NEW YORK, N. Y., A CORPORATION OE NEW YORK.

- TELEPEONE-EXOEANGE SYSTEM.

Application filed July 19 To all whom it may concern:

Be it known that we, HENRY P. CLAUSEN and CHARLES L. GOODRUM, citizens of the United States, residing at Mount Vernon, in the county of Westchester, State of New York, and at New York, in the county of New York and State of New York, respectively, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to improvements in telephone exchange systems and has particular reference to a circuit arrangement for switches.

In a trunk-hunting switch, it is desirable that the brushes, during the trunk-hunting operation, have access to a large number of terminals. This trunk-hunting occurs between the transmission of two sets of impulses by the calling. subscriber. It has I can found in practice that the speed of the switch is sufficient, in a reat majority of instances, to permit of the completion of the hunting operation before the second set of impulses is transmitted to operate a surceeding switch. However, should another set of impulses be started before a switch has found an idle trunk, certain of the impulses would be lost, which would result in the establishment of an incorrect connection.

An object of the present invention is to provide novel'means for preventing the incorrect setting of switches should Ea set of impulses be sent to operate a switch before a preceding one has completed its trunk-hunting operation.

In accordance with this object an impulsestoring mechanism is provided at a switch which will be operated to store impulses. intended for a succeeding switch if said impulses are transmitted before the first switch has completed its trunk-huntin eration. When an idle trunk is foun impulse-storing mechanism is released,

opthe and impulses are then transmitted therefrom to operate said succeeding switch.

The inventive idea involved is capable of receivin a variety of ex ressions one of which, or the purpose 0 illustrating the invention, is shown in the accompanying drawing; but it is to be expressly understood that said drawing is employed m rel Specification of Letters Patent. Patented J 1'7, 1922.

, 1919. Seria1N0.,,811,959.

for the purpose of facilitating the description of the invention as a whole and not to define the limits thereof, reference being had to the appended claims for this purpose.

In the drawing the figure illustrates diagrammatically a circuit arrangement and mechanism employed in carrying out the invention.

It is believed that the invention will be fully understood from the followin detailed description of the operation. Vhen a call is initiated by a subscriber removing the receiver from its switchhook at substation I, a circuit is closed to operate a line or finder switch (not shown) in a manner well known in the art. The operation of such a switch extends the calling line to an idle selector switch, such as shown in the drawing, whereupon a circuit is closed for line relay 2 extendin from grounded battery, right winding 0 said relay, side switch wiper 3 in position 1, apparatus at substation 1, side switch wiper 4 in position 1 and left winding of relay 2 to ground. Energization of relay 2 establishes a circuit for slow-to-release relay 5. The selector is now in condition to receive impulses transmitted from the sending device 6 at the calling sub-station to operate the switch in its primary or group selectin movement. The first deenergization of re ay 2 in response to the impulses, establishes a circuit for the second slow-to-release relay 7 extending from grounded battery, Winding of said relay, front contact and armature of relay 5 and back contact and armature of relay 2 to ground. Relays 5 and 7, being slow-to-release, maintain their armatures attracted during transmission of the impulses. Ener ization of relay 7 establishes a circuit for t e escape magnet 8 extending from grounded battery, windin of said magnet, side-switch wiper 9 in position 1, frontcontact and armature of relay 7 to ground. Magnet 8, in energizing at this time, has no effect upon the side-switch mechanism. Each deenergization of relay 2 also closes a circuit for primary stepping magnet 10,

traceable from grounded battery, winding 35 storing mechanism, contact spring 21, slid- 13 and 14 of the switch in accordance with whereupon contact 24.- is

the impulses transmitted to step said brushes in a group selecting movement. At the termination of the impulses relay 2 remains energized and thus opens the circuit for rela 7, which, after an interval, releases. The deenergization of relay 7 opens the circuit for magnet 8, which thereupon releases and moves the side-switch wipers into position 2. When side-switch wiper 15 moves into its second osition a self-interrupting circuit is estab ished for secondary stepping magnet 16 and "the brushes 12, 13

and 14 of the switch are stepped, in a trunkhunting movement, over the terminals of the selected group until an idle trunk is found, this condltion being denoted by ground at test terminal 17. When an idle trunk is reached a circuit is established for escape magnet 8, extendin from grounded battery, winding of said magnet, sideswitch wipers 9 and 18 in position 2, brush 14 and terminal 17 to round. Energizatiou of magnet 8 moves t e side-switch wipers osition 3.

if, during the trunk-hunting operation, sending device 6 has not been operated to transmit a second set of impulses intended for the next succeeding switch, the impulse storing mechanism, generally indicated by the numeral 19, will remain inactive. Escape magnet 8, upon reaching position 3,

will find another energizing circuit for itselfextending through the side-switch wiper 9, slid ng contact 37, contact 20 of the impulseing contact 38 and back contact and armature of relay 7 to ground. Magnet 8 will again energize and move side-switch wipers into position 4 whereupon relays 2 and 5 will release. The calling line is now extended to the next succeeding switch, which I is reached.

At the termination of a conversation, the replacing of the receiver upon the switch hook at substation '1, will cause a ground.

to be applied to release conductor 22, in a manner well-known in the art, and thus establish a circuit for release magnet 23. This magnet, in energizingTcloses a locking circuit for itself from through its winding, armature and front contact and oil-normal contact 24, which was closed upon the first step of the switch from its normal position, to ground. Magnet 23 operates to restore brushes 12, 13 and 14 and the side-switch mechanism to normal, opened and magnet 23 is thus permitted to release.'

Assuming now that While the side-. iwil ch grounded battery wipers are in. position 2 and the switch is performing its secondary or trunk-hunting operation, the calling subscriber manipulates sendin device 6 to transmit a second set of impu se's designed to operate a succeeding switch, relay 2 will respond to each interruption in the same manner as before. A circuit will then be established for magnet 25 of the impulse-storing mechanism 19,

side-swatch wipers @move into position 3,

magnet 25 would continue to step in response to the impulses over a circuit which now extends through side-switch wiper 11 in its third position. In response to each impulse, magnet 25 operates pawl 26 to step ratchet 27 in a counter-clockwise direction. Ratchet 27 is connected to impulse wheel 28 by a spring 28 or other similar device,

which will be tensioned as ratchet 27 is ro-' v tated so that wheel 28 will also be rotated when the same is released by the holding pawl 29 normally in engagement with a tooth thereof. Upon the first step of ratchet 27, contact 20 is disengaged from the spring contact 21 and contacts 30 and 31 are permitted to engage. This is accomplished by normally tensioning springs 21 and 30 by the pressure thereagainst of a pin 30 carriedby the impulse wheel 28. Therefore, should the switch find an idle trunk while the second set of impulses are still being transmitted and the side-switch wipers move into position 3, the previously described circuit for escape magnet 8, extendin through contacts 20 and 21, will not be c osed and the side-switch wipers will thus be prevented from moving into position 4 until ofi-normal contact 20 is restored. When sideswitch wiper 32 moves from position 2 into .necting ratchet 27 and whegl 28 and a speedcontrolling governor 27 of any well-known type, the wheel 28 is then rotated in a counter-clockwise direction and the teeth thereof operate lever 33 to open the contact 34. If at the end of the trunk-hunting operation, and after wheel '28 is released, impulses continue to be transmitted, the ratchet 27 will be stepped in the same manner as before and the storing mechanism will then simultaneously receive and send out the ime pulses.

The spring contacts 30 and 31 being now closed to bridge the telephone l ne and sidesucceeding switch in accordance with the impulses transmitted. As soon as impulse wheel 28 again assumes its normal position with respect to ratchet 27, pin 30' engages contact 30 to disengage it from contact 31 and at the 'same time cause spring 21 to again engage contact 20. The previously described energizing circuit for escape magnet 8, through contacts 20 and 21 is thereby again established and said magnet energizes to move side-switch wipers from position 3 into position 4.

\Vhen the side-switch wiper 32 is restored to normal upon the release of the switch, holding pawl 29 is again permitted to engage the impulse wheel 28 and the impulsestoring mechanism will be in position-to again be operated.

What is claimed is:

'1. In a telephone system, automatic switches having a plurality of movements, means for sending a series of impulses to operate one of said switches in its primary movement, means for operating such swltch in its secondary movement for extending a connection to the succeeding switch, means for transmitting a subsequent series of impulses over said connection to operate the succeeding switch, a register device, and means for rendering said subsequent series effective to set the register device when sent before the completionof the secondary movement of the to set the register device when sent before the completion of the secondary movement of the first mentioned switch, and means for operating the register device to send a series of impulsesto the succeeding switch (orresponding to said subsequent series.

In a telephone system a line, automatic switches having a plurality of movements, a. sender for sending series of impulses over said line to operate one of said switches in its primary movement, means for operating said switch in its secondary movement for extending a connection to the succeeding switch, means for transmitting a subsequent series of impulses sent over said .line to the succeeding switch provided the first mentioned switch has completed its secondary movement prior to the sending of the subsequent series, a register device, means for rendering the subsequent series of impulses eifective to set said register device when sent before the completion of the secondary movement of the first mentioned switch, and means for subsequently operating the register device to transmit a series of impulses to the succeeding switch.

4. In a telephone system, automatic switches having a plurality of movements, means for sending a series of impulses to operate one of said switches in its primary movement, means for operating such switch in its secondary movement to extend a connection to the succeeding switch, means for transmitting a subsequent series of impulses over said connection to operate the succeeding switch, a register device, means for rendering said subsequent series of impulses effective to set the register device when sent before the completion of the secondary movement of the first mentioned switch, and a switch auxiliary to said first mentioned switch operable to start said register device in operation to transmit a series of impulses corresponding to said subsequent series to the succeeding switch.

5. In a telephone system, a train of automatic switches having primary and secondary'movements, an impulse sender for setting the first switch in its primary movement, means thereupon automatically operated to give said switch a secondary movement to select an idle trunk, an impulse storing mechanism operatively assoclated with said sender during such hunting movement and set thereby should said sender be operated before the idle trunk is seized, means operated by the seizure of the idle trunk and restoration of the sender for causing said impulse storing mechanism to operate to set the succeeding switch in its primary movement, and means actuated should the trunk be seized before the sender is operated to disassociate the impulse storing mechanism from the sender and render the latter effective to control the succeeding switch in its primary movement.

- In witnesswhereof, we hereunto subscribe our names this 17th day of July, A. D. 1919.

HENRY P. CLAUSEN. CHARLES L. GOODRUM. 

